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Finding the Fourth Proportional to 27.27, 40.79 and 21.20

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Solution

The fourth proportional to 27.27, 40.79 and 21.20 is: 31.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.27 : 40.79 = 21.20 : x
  2. Step 2: Convert to fraction form
    27.27/40.79 = 21.20/x
  3. Step 3: Cross multiply
    27.27x = 40.79 × 21.20
  4. Step 4: Simplify right side
    27.27x = 864.44
  5. Step 5: Solve for x
    x = 864.44/27.27
  6. Step 6: Final answer
    x = 31.70

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.